This invention relates to the field of portable night vision apparatus of the hand-held and self-illuminating type.
Infrared spectrum responsive night vision apparatus has become a necessary part of modern military equipment. The ability to see objects that are in total darkness but illuminated with infrared energy has been demonstrated in the recent Desert Shield and Desert Storm military endeavors and elsewhere to now be a major tactical advantage. Indeed, the ability to see an opponent and his military hardware under totally invisible conditions to the unaided eye has now removed the advantage of nighttime and smoke screen obscured military activity.
Much of the presently used infrared military equipment is intended for operation in an aircraft, a battle tank, a motor vehicle or in a fixed location environment. The now-current third-generation night vision apparatus, however, has energy requirements, physical dimensions, and weight characteristics which readily enable successful portable use of such equipment. A small hand-held and truly portable night vision apparatus, especially an apparatus of simplicity and low cost, has, however, not been widely available heretofore.
The patent art includes several examples of night vision apparatus or infrared energy responsive apparatus that is of general background interest with respect to the present invention. Included in this art is the patent of T. M. Brennan et al, U.S. Pat. No. 4,463,252, relating to a battery-operated night vision goggle system of the two-eye and ambient vision excluding type.
Also included in this art is the night vision viewing system of S. M. Ellis as disclosed in U.S. Pat. No. 4,775,217, a system of the helmet mounted two-eye type.
Additionally included in this art is the infrared zoom illuminator of R. A. Simms as is disclosed in U.S. Pat. No. 4,948,210. The Simms illuminator contemplates the use of an infrared laser light source and an optical lens system by which the emitted infrared energy may be disposed in the form of a floodlight or a spotlight.
Additionally included in this art is the semi-active night viewing system of F. R. Loy as disclosed in U.S. Pat. No. 4,642,452, an apparatus for television camera usage wherein a flash of laser diode sourced light is used for identification of a specific target.